JP2002515268A - Syringe assembly - Google Patents

Abstract

SUMMARY A syringe assembly (10) includes a syringe barrel (12) having an inner surface (22) and a substantially closed discharge end (24) defining a discharge opening (26). Including. A stopper (34) rests on the inner surface (22) of the syringe barrel (12). The piston (14) is slidably disposed within the syringe barrel (12). The piston has a frontmost sealing surface and a rearmost sealing surface. The foremost sealing surface (39) and the rearmost sealing surface (45) are separated from each other by a first distance. The piston (14) is movable between a first position and a second position. The plunger rod (18) has at least one finger (76) extending therefrom that engages the stop (34) when the piston (14) is in the second position. Having a distal end configured to operate. The distal end of the at least one finger (76) is located no more than a first distance from the stop (34) when the piston (14) is in the first position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention broadly includes a syringe assembly that includes a syringe barrel and is capable of advancing a slidable piston into the barrel to dispense fluid contained within the syringe barrel. About. More specifically, the present invention relates to a syringe assembly configured to provide an indication when the slidable piston is withdrawn to a predetermined limit.

BACKGROUND ART A typical syringe assembly includes a plunger assembly and a hollow (usually cylindrical) syringe barrel. The plunger assembly typically includes a slidable piston and a plunger rod. The syringe barrel includes a substantially closed discharge end defining a discharge opening and a substantially open end for receiving a front end of the plunger assembly opposite thereto. including. The piston is usually cylindrical and slidable within the cylinder. The peripheral end of the piston is in sealing engagement with the inner surface of the syringe barrel. As the piston is moved toward the discharge end, fluid is forced out of the syringe barrel through the discharge opening. As the piston moves toward the open end, fluid is drawn into the syringe barrel.

[0003] Some syringe assemblies are pre-filled. That is, the syringe assembly is filled at the time of manufacture rather than at the time of use. In these syringe assemblies, the discharge opening is sealed after the fluid is introduced into the fill chamber defined by the area between the piston and the syringe assembly and the position of the foremost seal and the discharge opening. The plunger rod may be attached to the piston during manufacture of the syringe assembly, or may be separate from the piston until the syringe assembly is used. Filling of the syringe may be performed aseptically. Alternatively, after filling, the syringe assembly can be terminally sterilized using various known sterilization methods.

[0004] The filling chamber and the fluid contents therein are sterilized. However, the exterior of the syringe barrel, as well as a portion of the interior of the syringe barrel located behind the piston, plunger rod, and the last seal created between the piston and the inner surface of the barrel, are exposed to the external environment of the syringe, It is difficult to maintain the sterility of said part of the syringe. Thus, if the piston is retracted beyond a certain limit, i.e., the original position of the rearmost seal between the piston and the syringe barrel when the syringe assembly and its contents are sterile, the fluid content of the barrel will increase. It will contact areas that may have been exposed to the non-sterile environment before retraction, thereby compromising the sterility of the fluid in the barrel.

[0005] The sterile portion of the syringe assembly is the last seal created between the piston and the inner surface of the syringe barrel after sterilizing the syringe if using a terminal sterilization method or after filling the syringe if using a sterile filling method. Is defined as the area between the position and the discharge opening.
To maintain sterility of the fluid content of the syringe, do not retract the piston so that the aft seal created between the piston and the interior of the syringe barrel moves outward to the point away from the sterile portion of the syringe assembly. is important. To prevent the rear seal from moving past the sterilization chamber, limit the withdrawal of the piston to no more than the distance between the rear and front seals (this distance is defined as the sterilization withdrawal limit). There must be. It is desirable to provide an indicator or stopper on the interior of the syringe barrel or on the plunger assembly to indicate that the sterile withdrawal limit has been reached.

[0006] Syringe assemblies are used to deliver a wide range of fluid volumes to a patient. Due to manufacturing costs, it is desirable to standardize the components used in manufacturing syringe assemblies so that a single syringe assembly model can be used to deliver a wide range of volumes. A wide range of capacities can be divided into multiple families. The various volumes included in one family are those volumes that can be accommodated by using standardized components of the syringe barrel, piston and discharge end cap in conjunction with a volume specific plunger rod. That is, standardized components can be created using standard equipment, and assembly, filling, and sterilization can be performed using standard equipment.

SUMMARY OF THE INVENTION The present invention is directed to a syringe assembly. The syringe assembly includes a syringe barrel having an inner surface. The syringe barrel further includes a substantially closed discharge end defining a discharge opening communicating fluid between the interior of the syringe barrel and the external environment of the syringe barrel. Also includes an end that is substantially open at a position opposite the discharge end that is closed at the end. A stopper rests on the inner surface of the syringe barrel.

[0008] The piston is slidably disposed between the substantially closed discharge end and the stopper in the syringe barrel. The piston has a front sealing surface and a rear sealing surface, and the front sealing surface and the rear sealing surface respectively form a fluid-tight seal between the piston and the inner surface of the syringe barrel. It is configured as follows. The foremost sealing surface and the last sealing surface are mutually separated by a first distance (first d).
istance) away. The piston is movable within the syringe barrel between a first position and a second position, the second position being between the first position and the substantially open end of the syringe barrel.

[0009] The syringe assembly further includes a plunger rod having a front end configured to engage a piston. The plunger rod has at least one finger extending therefrom. The at least one finger includes a distal end configured to engage a stop resting on the inner surface when the piston is in the second position. The distal end of the at least one finger is located no more than a first distance from a stopper resting on the inner surface of the syringe barrel when the piston is in the first position.

[0010] Numerous other advantages and features of the present invention will be readily understood from the following detailed description, the appended claims, and the accompanying drawings, which disclose the details of the invention fully and fully as part of the specification. Will be done.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of components of a syringe assembly constructed in accordance with the present invention; FIG. 2 is a syringe assembly of the present invention when the plunger rod is in an initial position. FIG. 3 is a cross-sectional view of the syringe assembly of the present invention when the plunger rod is in the sterile withdrawal limit position; FIG. 4 is before the plunger rod is fully inserted into the syringe barrel. FIG. 5 is a cross-sectional view of a portion of the syringe assembly of the present invention; FIG. 5 is a cross-sectional view of a portion of the syringe assembly of the present invention with a plunger rod partially inserted into a syringe barrel; FIG. 4 is a cross-sectional view of a portion of the syringe assembly of the present invention with the rod at the sterile withdrawal limit.

DETAILED DESCRIPTION While many different embodiments of the present invention are possible, specific embodiments of the present invention are illustrated in the accompanying drawings and are described in detail herein. However, the disclosure of this specification is to be regarded as illustrative of the idea of the present invention, and is not intended to limit the present invention to the specific examples illustrated herein.

Referring now to the embodiment of the invention shown in the accompanying drawings, the syringe assembly 10
Includes a syringe barrel 12, a slidable piston 14, a discharge end cap 16 and a plunger rod 18. The plunger rod 18 includes a sterile withdrawal limit indicator 20. The syringe barrel 12, piston 14, and discharge end cap can be made as standardized components for use in delivering a wide range of volumes of fluid to a patient. However, it is preferred that the plunger rod 18 be configured such that one plunger rod 18 can be used to deliver a specific volume of fluid to a patient in a volume-specific manner. Plunger rod 18
May have a fixed length. However, the position of the sterile withdrawal limit indicator 20 will vary depending on the volume of fluid to be delivered. Alternatively, the position of the sterile withdrawal limit indicator 20 may be standardized to a fixed distance from the rearmost end of the plunger rod 18 such that only the entire length of the plunger rod 18 differs by volume specific size.

The syringe barrel 12 is hollow and defines an inner surface 22 and a substantially closed discharge end 24. The discharge opening 26 is defined by the discharge end 24 of the syringe barrel 12. In one embodiment of the present invention shown in the accompanying drawings, the discharge opening 26 comprises:
It is configured to connect to a device having a rock lure structure. However, it is recognized that the discharge opening can be configured to connect to various other devices. For example, the drainage opening 26 may be configured to connect to a hypodermic needle or non-lock luer.

The syringe barrel 12 is substantially open at the open end 28. The open end 28 is configured such that the piston 14 and the plunger rod 18 can be slidably positioned within the syringe barrel 12. A flange 32 radially extends outward from the syringe barrel 12 near the open end 28. Flange 32 functions as a tab to facilitate use of syringe assembly 10 of the present invention.

A piston stopper 34 extends radially inward from the inner surface 22 of the syringe barrel 12 at a predetermined location. The above-mentioned position is selected depending on the volume of the fluid to be delivered to the patient and / or the shape of the plunger rod 18 as described above. The piston stopper 34 can have a variety of shapes, including an inwardly projecting annular ring 34a, one or more protrusions inwardly projecting from the inner surface 22, or other portions of the syringe barrel 18. Includes, but is not limited to, one or more depressions along the smooth inner surface 22. Piston stopper 34 is configured to interact with sterile withdrawal limit indicator 20 to provide an indication that the sterile withdrawal limit of syringe assembly 10 has been reached, as described in detail herein.

The syringe barrel 12 and the piston stopper 34 may be integrally formed, or may be formed as separate parts and then connected to each other using a known forming and connecting method. Syringe barrel 12 and piston stopper 34 can be made from a variety of materials that do not chemically interact with the medicament over an extended period of contact.

The piston 14 includes a front portion 36 having a front surface 37 and an annular front end 38.
including. Piston 14 also includes a rear portion 42 having a rear surface 43 and an annular rear end 44. Both the front end 38 and the rear end 44 slidably seal against the inner surface 22 of the syringe barrel 12 to define a front seal 39 and a rear seal 45, respectively. The piston 14 of the present invention can have various configurations without departing from the spirit of the present invention described in the appended claims. That is, the piston 14 may be substantially cylindrical so as to make sealing contact with the inner surface 22 over its entire length. Piston 14 may also be configured with two or more ends in sealing contact with inner surface 22 of syringe barrel 12. Preferably, the piston 14 is also made of a material that does not chemically interact with the drug over an extended contact period.

The rear surface 43 is configured to engage the plunger rod 18 so that the plunger rod 18 can exert a sliding movement on the piston 14. Rear surface 43
Can be configured to include a threaded socket 45 configured to threadably receive a threaded member 48 against the plunger rod 18. Alternatively, the rear surface 43 may be configured to receive and frictionally retain a portion of the plunger rod 18 therein. In any of the above embodiments, the reciprocating motion of the piston 14 can be imparted by the plunger rod 18 to cause a mechanical connection between the piston 14 and the plunger rod 18.

The discharge end cap 16 is also preferably made from a material that does not interact with the medicament over an extended period of contact. The discharge end cap 16 is attached to the syringe barrel 12
The cap is fitted with a discharge opening 26 to prevent the contents of the
Are fluidly sealed. The discharge end cap 16 is also preferably configured to prevent contaminants from entering the syringe barrel 12 to maintain sterility of the contents of the syringe barrel 12. The discharge end cap 16 can take various shapes, depending on the shape of the discharge opening 26 and the shape of the fluid transfer device that is in fluid connection with the syringe assembly 10.

The plunger rod 18 can have various shapes, including a substantially cylindrical shape. However, in the embodiment of the invention shown in the accompanying drawings, the plunger rod 18 is defined by four vanes 80 arranged substantially perpendicular to each other. Plunger rod 18 further includes a front end 54 configured to engage piston 14 as described above. The rear end 55 of the plunger rod includes a push surface 56 configured to engage with a user's hand or with a syringe pumping device.

As noted above, plunger rod 18 further includes a sterile withdrawal limit indicator 20. The position of the indicator 20 on the plunger rod 18 is determined by the predetermined fill volume of the syringe assembly 10 and the position of the stopper 34. The indicator 20 engages with the stopper 34 by which the syringe barrel 12
The piston 14 and the plunger rod 18 can be configured to be prevented from being further withdrawn. In another embodiment shown in the accompanying drawings, indicator 20 and stopper 34 are configured to provide tactile indication to a user of syringe assembly 10 when they come into contact. In other words, the indicator 20 and the stopper 34 can be pulled out beyond the stopper 34 by the indicator 2.
It is configured so that it is more difficult than pulling out 0 from the original position to the stopper 34. The generated tactile signal allows the user to move the piston 14 and the plunger rod 18
It is indicated that further withdrawal may compromise the sterility of the contents of the syringe assembly 10. However, it is possible for the user to further withdraw the piston 14 and the plunger rod 18 from the syringe barrel 12 by applying an outward force large enough to eliminate the interaction between the indicator 20 and the stopper 34. is there.

In the embodiment of the invention shown in the accompanying drawings, the indicator 20 includes one or more flexible cantilever fingers 76 that extend radially outward and rearward relative to the plunger rod. Each finger 76 extends radially outward slightly beyond the periphery of the wing 80 such that the finger 76 engages the stop 34. The outer radius of the finger 76 may be less than, equal to, or greater than the diameter of the inner surface 22 of the syringe barrel. Preferably, the flexible flange is configured to flex so that the plunger rod 18 can be inserted into the syringe barrel 12 beyond the stop 34 when the syringe assembly 10 is assembled. When the plunger rod 18 moves through the syringe barrel 12, the blade 80
It is preferable to configure so as not to engage with No. 4.

Preferably, the angle of the finger 76 with respect to the vane 80 is selected such that the rod is easily inserted without applying extra force. The preferred angle of finger 76 is determined by a number of factors, such as the material used to make finger 76, the thickness of finger 76, and the amount of radial overlap between stopper 34 and finger 76. The preferred angle of finger 76 is such that the force required to insert plunger rod 18 beyond stopper 34 into syringe barrel 12 is the force required to pull plunger rod 18 beyond stopper 34 and out of syringe barrel 12. It is preferred that the selection be made less.

When the longitudinal distance between the foremost seal 39 and the rearmost seal 45 that occurs between the piston 14 and the inner surface 22 is “x”, the syringe assembly 10 is configured to be in a filled, sterile condition. The stopper 34 is moved a distance “x” after the position of the indicator 20.
It will be appreciated that the maximum fill volume of the syringe assembly 10 is achieved when the indicator 20 is near the rearmost seal 45. However, the indicator 20 and the stopper 34 As long as the relative position described above is provided, the indicator 20 can be provided at a desired position on the plunger rod 18.

The piston 14 of the syringe assembly 10 of the present invention comprises a piston 14 and an inner surface 22.
The total longitudinal distance "x" equal to the distance between the foremost and last seals in between may be retracted. When the withdrawal distance between the plunger rod 18 and the piston 14 is less than or equal to "x", the medicament contained within the syringe barrel 12 is physically associated with portions of the syringe assembly 10 that may have been exposed to non-sterile conditions. Contact will certainly be eliminated. If the distance between the plunger rod 18 and the piston 14 exceeds “x”, the sterility of the medicine may be impaired.

A method for assembling a pre-filled syringe assembly 10 according to the present invention will now be described. As noted above, for the fill dose family, each of the syringe barrel 12, piston 14 and discharge end cap 16 has a single size and shape. Preferably, plunger rod 18 is manufactured in a unique size and shape for a given fill dose of syringe assembly 10.

In the first step of the assembling method, a syringe barrel 12 configured as described above is prepared and supplied to an assembling machine. The above-described piston 14 is prepared, and the syringe barrel 12 is prepared.
At the open end 28 of the. The piston 14 is advanced through the syringe barrel 12 until the piston 14 approaches or contacts the discharge end 24 of the syringe barrel 12. Next, a predetermined dose of the fluid medicine is prepared and introduced into the syringe barrel 12 through the discharge opening 26. This causes the piston 14 to move a volume-related distance toward the substantially open end 28 of the syringe barrel 12. The outlet opening 26 of the syringe barrel 12 is then closed using the outlet end cap 16.

The method described above assembles all of the components of the syringe assembly 10 and the medicament.
It can be performed by a sterile filling method in which the filling is sterilized before filling and the filling and closing of the lid are performed under aseptic conditions. Alternatively, after filling the medicament, the medicament and syringe assembly 10 may be finally sterilized by known sterilization methods. The sterilization methods include, but are not limited to, heat sterilization and UV sterilization.

The attachment of the plunger rod 18 to the piston 14 can be performed at any point in the method. That is, the plunger rod 18 (a) before inserting the piston 14 into the syringe barrel 12, (b) before filling the syringe barrel 12 with a medicine,
It can be attached to piston 14 before (c) final sterilization of syringe assembly 10 or (d) when using syringe assembly 12.

In a preferred embodiment of the present invention, the particular configuration of plunger rod 18 is selected when administering a medicament from syringe assembly 10 to a patient, and the configuration of plunger rod 18 is contained within syringe assembly 10. Determined by the volume of drug to be delivered to the patient.

To administer the medicament contained in the syringe assembly 10 to the patient, the discharge end cap 16 is removed from the discharge opening 26. At this point, the slidable piston 14 and plunger rod 18 can be withdrawn to the sterile withdrawal limit without the risk of contaminating the fluid contents of the syringe assembly. Syringe assembly 1
A user of zero knows when the limit has been reached by one or more fingers 76, a haptic signal generated when the indicator 20 engages the stop 34.

From the foregoing, it will be apparent that many modifications and variations can be made without departing from the true spirit and scope of the novel concept of the present invention. The disclosure herein is merely illustrative of the invention and is not intended to limit the invention to the particular embodiments illustrated. It is to be understood that the disclosure herein is intended to cover all modifications within the scope of the present invention by the appended claims.

[Brief description of the drawings]

FIG. 1 is a perspective view of components of a syringe assembly constructed in accordance with the present invention.

FIG. 2 is a cross-sectional view of the syringe assembly of the present invention when the plunger rod is in an initial position.

FIG. 3 is a cross-sectional view of the syringe assembly of the present invention when the plunger rod is in a sterile withdrawal limit position.

FIG. 4 is a cross-sectional view of a portion of the syringe assembly of the present invention before the plunger rod is fully inserted into the syringe barrel.

FIG. 5 is a cross-sectional view of a portion of a syringe assembly of the present invention with a plunger rod partially inserted into a syringe barrel.

FIG. 6 is a cross-sectional view of a portion of the syringe assembly of the present invention with the plunger rod at a sterile withdrawal limit.

Claims (7)

[Claims] 1. A substantially closed discharge end defining an inner surface, a discharge opening for communicating fluid between the interior of the syringe barrel and the external environment of the syringe barrel, and the substantially closed end. A syringe barrel having a substantially open end opposite the discharge end being provided, a stopper mounted on an inner surface of the syringe barrel, substantially within the syringe barrel. A piston slidably disposed between a closed discharge end and a stopper, the piston having a frontmost sealing surface and a rearmost sealing surface, wherein the frontmost sealing surface and the rearmost sealing surface are provided. The sealing surfaces are each configured to provide a fluid tight seal between the piston and the inner surface of the syringe barrel, the foremost sealing surface and the rearmost sealing surface being a first distance apart from each other, Fixie Is movable between a first position and a second position, said second position being the piston between the first position and the substantially open end of the syringe barrel; and A plunger rod having a front end configured to engage the piston, the plunger rod having at least one finger extending therefrom, wherein the at least one finger moves the piston to a second position. Has a distal end configured to engage a stop resting on the inner surface when the piston is in the first position.
Wherein said plunger rod is positioned no more than a first distance from a stopper mounted on the inner surface of the syringe barrel when in the position. 2. The plunger rod comprises four blades arranged substantially perpendicular to each other, at least one finger having at least one of said blades.
The syringe assembly according to claim 1, wherein the syringe assembly is defined by a single piece. 3. The plunger rod of claim 1, wherein at least one finger extends radially outward from the plunger rod, and at least one finger extends away from a front end of the plunger rod. 2. The syringe assembly of claim 1. 4. The syringe assembly further includes a cap configured to fluidly seal the discharge opening, wherein the cap is configured to releasably rest on the syringe barrel. The syringe assembly according to claim 1, characterized in that: 5. The syringe assembly according to claim 1, wherein the syringe assembly further comprises a medicament disposed between the piston and the substantially closed discharge end within the syringe assembly. Syringe assembly. 6. A method comprising providing a syringe assembly and forcing the medicament through a discharge opening defined by a substantially closed discharge end by applying an inward force to the plunger rod. A method of delivering a medicament to a patient, wherein the syringe assembly is substantially closed defining an outlet opening for communicating fluid between an inner surface and an interior of the syringe barrel and an external environment of the syringe barrel. A syringe barrel having a discharge end that is positioned and a substantially open end opposite the substantially closed discharge end, mounted on an inner surface of the syringe barrel. A piston slidably disposed between a substantially closed discharge end in the syringe barrel and the stopper, the piston being a foremost seal. A front surface and a rear sealing surface, wherein the front sealing surface and the rear sealing surface are each configured to provide a fluid-tight seal between the piston and the inner surface of the syringe barrel; The sealing surface and the rearmost sealing surface are separated from each other by a first distance, the piston is movable between a first position and a second position, and the second position is different from the first position. A piston located between the substantially open end of the syringe barrel, a medicament located between the piston in the syringe barrel and a substantially closed discharge end, and A plunger rod having a front end configured to mate with said plunger rod having at least one finger extending therefrom, said at least one finger having a piston. And a distal end configured to engage a stop resting on the inner surface when in the second position, wherein the distal end of the at least one finger is a piston 1
Wherein said plunger rod is at a position no more than a first distance from a stopper mounted on the inner surface of the syringe barrel when in the position. 7. The method according to claim 1, wherein, before applying an inward force to the plunger rod, the piston is moved from the first position to the second position by applying an outward force to the plunger rod. A method for delivering a drug to a patient according to claim 6.